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  1. T3TRIS

    Problems with keeping 302Ah in balance

    Well, never mind… I connected the battery with those beautifully balanced 280Ah cells and cell #4 triggered the over voltage protection (though they were all much closer to one another than the 302Ah). So... my 60A power supply can spit out 14.4V (at the end of the leads) at 50A and the...
  2. T3TRIS

    Problems with keeping 302Ah in balance

    Huh? In AGM setting, the charger will do boost charge and absorption at 14.4V, then float at 13.5V. In lithium, it's the same but at 14.5V, then float at 13.6V. Avoid 13.5V?
  3. T3TRIS

    Problems with keeping 302Ah in balance

    Right? Their charging voltages are 14.4V for GEL/AGM (13.5 float) and 14.5 (13.6 float) for Lithium. It's close to 14.6V though!
  4. T3TRIS

    Problems with keeping 302Ah in balance

    I don’t disagree with any of your inputs and I truly wish I could customized the Redarc Manager30’s charging profile to lower its voltage to more manageable values, but there it is… 14.4V is what I have to work with (there’s no changing that charging system, though I guess I can contact Redarc...
  5. T3TRIS

    Problems with keeping 302Ah in balance

    Thanks again for all the inputs and the OCD reality check :) Here's where my OCD seems to pay though... I swapped the 302Ah CATL cells for the 280Ah EVE cells that I had laying around. Did a top balance on those followed by a quick capacity test (around 274Ah). The cells' voltages were never...
  6. T3TRIS

    Problems with keeping 302Ah in balance

    Ok, I read that before. Some people say to leave it running all the time and some others say only while charging and above 3.4V. The balancer I got isn't all that fancy... Is it really a problem to leave these connected 24/7? This is an oversized battery for the application. As far as adjusting...
  7. T3TRIS

    Problems with keeping 302Ah in balance

    Alright, new update. I've installed the 5A balancer (so easy!!!) and I think it works, at least the little diode is on. I put a 25A load on the batter for 20min or so to try to shave off some of that cell saturation, then re-connected the charger. The charger chugged along at 30A, as expected...
  8. T3TRIS

    Problems with keeping 302Ah in balance

    Interesting idea... I've wanted to use voltage triggered relays to enable battery heating in the past (when the relay detects that the alternator is going). I think I'm going to see if the system works on GEL/AGM setting first, along with an active balancer. That seems like the simplest method...
  9. T3TRIS

    Problems with keeping 302Ah in balance

    Thanks everyone, I think this is what I needed to be told a few times before it sinks in... I'll still look at the active balancing. I guess I have to make sure it only happens periodically (thanks for the tip The Good Package). It's too bad, it's been fun to build these batteries but yeah...
  10. T3TRIS

    Problems with keeping 302Ah in balance

    Thanks! I’ll have to look into that channel. I agree with your methodology… I just am not sure I can change the charging voltage for this charger. Maybe I’ll look at their other charging profiles to see if one has a lower voltage but same absorption voltage.
  11. T3TRIS

    Problems with keeping 302Ah in balance

    Thanks for the detailed response. Yeah, everything seems kind of OK enough, but I'm not happy with the way these cells interact once they are in the system. The Redarc Manager30 charges at 30A and 14.5V and has some charging profiles. The few times I've tried to keep an eye on it, it seems that...
  12. T3TRIS

    Problems with keeping 302Ah in balance

    This battery cell grading system is so annoying… I’m really tired of this kind of market manipulations (which apparently just happens anywhere). I know not to trust Grade A from AliExpress, however I was hoping that since it was recommended by Will Prowse, I could trust the darn things (though...
  13. T3TRIS

    Problems with keeping 302Ah in balance

    These were advertised as grade A from a shop that was recommended by Will… I can’t see the recommendation on his site anymore, so maybe they got worse…
  14. T3TRIS

    Problems with keeping 302Ah in balance

    Hello, I built a 302Ah battery pack using 302Ah CATL grade A cells from EELbattery (if memory serves, the seller was recommended by Will Prowse at the time I purchased). The cells are connected using flexible busbars (same seller), they are dynamically compressed using die springs and 1/8...
  15. T3TRIS

    LiFepo4 top balancing equipment recommendations

    Here's another update. I ended up using the 60A power supply to do some top-balancing after all. What I did was set the power supply to around 3.500V and let it do its thing. I checked it every now and then with the voltmeter to make sure things were working right. When the amperage dropped...
  16. T3TRIS

    LiFepo4 top balancing equipment recommendations

    Oh yeah, thanks for the reminders on all of it :) The power supply didn’t even come with leads and the high amperage terminals are definitely in the rear (the front is 10A max). I had already made 6AWG cables with proper hydraulically crimper terminals for it. I also tinkered with it more and...
  17. T3TRIS

    LiFepo4 top balancing equipment recommendations

    Another option is this 0-15V 60A power supply. I just received mine a couple hours ago and will test it: HUIOU KXN-1560D Adjustable Switching DC Power Supply 0-15V 0-60A https://www.amazon.com/dp/B0856ZP4MR/ref=cm_sw_r_cp_api_gl_i_HNTTD1AA5M5Z4GVDNTVX?_encoding=UTF8&psc=1 I imagine it’ll have...
  18. T3TRIS

    320Ah LiFePO4 4S battery build with AliExpress cells, Overkill BMS and compression box

    Thanks!! That's cool! Yeah the box I have here is workable but not ideal. Securing it to the van has been its own dilemma but it's been workable so far. The whole solid toolbox approach is nice. I think I'll definitely end up using some sort of strap to hold it though, rather than this solid bar.
  19. T3TRIS

    320Ah LiFePO4 4S battery build with AliExpress cells, Overkill BMS and compression box

    Actually, I’m familiar with 2P4S configurations and that wasn’t what I was asking. What I meant was that I’m not sure how a 2P4S configuration is relevant to this discussion (I could’ve been more clear in my question I guess). I built a 4S configuration to have a compact 320Ah 12V battery...
  20. T3TRIS

    320Ah LiFePO4 4S battery build with AliExpress cells, Overkill BMS and compression box

    I’m not entirely sure what you mean with this.
  21. T3TRIS

    320Ah LiFePO4 4S battery build with AliExpress cells, Overkill BMS and compression box

    Thanks! It's been a fun project for sure. My question about drilling holes is more for the safety vent valves on the cells themselves though. I guess people who have had catastrophic failures had their cells vent out through those valves. Should this happen to us (hopefully not obviously), I...
  22. T3TRIS

    320Ah LiFePO4 4S battery build with AliExpress cells, Overkill BMS and compression box

    I've been trying to figure out the best way to secure the battery pack to our van and it hasn't been easy. I went through the trouble of making a "compression" box, so I guess I need to make sure that the compression is not inhibited by securing it to the vehicle. This is even more challenging...
  23. T3TRIS

    320Ah LiFePO4 4S battery build with AliExpress cells, Overkill BMS and compression box

    Excellent input. I had no idea that the BMS shouldn't be used for that purpose. I read the Overkill Solar BMS instructions from cover to cover, and unless I missed that or forgot about it, I don't think that is mentioned in there. I guess it makes sense now that I think about it, no need to have...
  24. T3TRIS

    320Ah LiFePO4 4S battery build with AliExpress cells, Overkill BMS and compression box

    Hey everyone, I've learned quite a bit from browsing other people's posts and builds (especially from Dan-O's post) so I figured I'd share my own attempt at building a LiFePO4 battery system. The goal is to add an auxiliary battery to our beloved 4WD 1987 Volkswagen Vanagon, which has no...
  25. T3TRIS

    Dan-O's DIY 105ah LiFePO4 cell holder springy contraption things!

    All good stuff in this thread. I still need to refine a few things but here’s the box so far. I had to reinforce the “cutting boards” as they were flexing a little. I also need different springs. The ones I used are supposedly rated to 190lbs or so but collapsed with 70lbs. I think I should also...
  26. T3TRIS

    Dan-O's DIY 105ah LiFePO4 cell holder springy contraption things!

    Oh I see, that's cool! Just to add a wrench in there, I'm also keeping in mind that we're talking about compressing to get 3,500 life cycles instead of 2,500 uncompressed... These batteries will most likely never be cycled fully more than 5 times month (averaged over an entire year). Even...
  27. T3TRIS

    Dan-O's DIY 105ah LiFePO4 cell holder springy contraption things!

    Very fancy Costco polypropylene and polyethylene cutting boards... turns out they flex a tiny bit, I'm about to reinforce them with some strategically placed extruded aluminum. I'll share photos when I'm done with that part. Thanks for sharing those ideas. I'll take a look at the video. I think...
  28. T3TRIS

    Dan-O's DIY 105ah LiFePO4 cell holder springy contraption things!

    Hey so I'm late to the party here, but I've been browsing this site looking for inspiration for compression boxes. Your build is one of the cleanest I've found and resembles what I had in my mind (albeit with 4 larger cells). I've got the sides and springs figured out, but am still working on...
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